/* 超链接当前选中式样 */
.current {
    color: #fff;
    text-decoration: none;
    background-color: #3b5998;
}
/* 未读红点
<span class="red-point">hello world</span>
 */
.red-point{
          position: relative;
        }

.red-point::before{
          content: " ";
          border: 3px solid red;/*设置红色*/
          border-radius:3px;/*设置圆角*/
          position: absolute;
          z-index: 1000;
          right: 0%;
          margin-right: -5px;
          margin-top: -5px;
}